Thick sectional welds are usually made in several passes. In this regard, it should be understood that the area between two adjacent parts to be joined is filled up a portion at a time. In the testing of such thick sectional welds, ultrasonic sensors and other nondestructive evaluation methods are often used to inspect same. However, under most circumstances, this inspection is almost always done a long time after the welding process has been completed and the weld has cooled down. It has long been known that when welding defects are detected on a pass-by-pass basis, they can be easily repaired before being covered by the welding material laid down by subsequent welding passes. Thus, for example, a defect in the root pass can be repaired easily and economically without grinding out all of the welding metal from the later passes. This welding method contrasts with inspecting a completed weld, because a significant amount of weld metal may have to be subsequently removed to reach the welding defect. Still further, and as discussed in U.S. Pat. No. 4,712,722, a significant economic and productivity advantage can be obtained if welding flaws can be substantially, concurrently detected and repaired on a pass-by-pass basis.
In U.S. Pat. No. 4,712,722, the teachings of which are incorporated by reference herein, several forms of a method and device which implements a pass-by-pass inspection of partially completed welds are described. While the apparatus and method described in that patent has worked with some degree of success, several shortcomings have been identified which have detracted from its usefulness. For example, it has been discovered that the method and apparatus as described in the earlier U.S. Pat. No. 4,712,722, is not completely satisfactory for inspection of all weld geometries.
Still further, the method and apparatus as described in U.S. Pat. No. 4,712,722, does not locate with any degree of precision, the precise location of the weld defect. Yet still further, the method and apparatus as described in U.S. Pat. No. 4,712,722, does not appear to provide a convenient means for verifying the presence of a welding defect.
In view of the foregoing, it would be highly desirable to provide a method and apparatus which can address these perceived and other shortcomings in a novel device and method which facilitates the concurrent nondestructive evaluation of partially completed welds.